Once phase II study PALA (NSC 224131) has been used at a dose of 1500 mg/m2 IV daily for 5 days for patients with metastatic adenocarcinoma of the colon or rectum. Twenty-one patients have been treated to date, 6 of whom have had no prior chemotherapy, with the remainder being treated after failure of other chemotherapeutic agents. No patient has shown regression of disease enough to qualify for a partial remission. There have been two patients who have shown stabilization of disease for periods up to six months. The predominant toxicities seen with PALA have been diarrhea and erythromatous skin rash which has been seen in every patient. Myelosuppression has not been a problem. PALA does not appear to have any activity in patients with metastatic carcinoma of the colon or rectum.